Buggy code:
private static volatile int maxHintWindow = DatabaseDescriptor . getMaxHintWindow ( ) ; private static volatile int maxHintsInProgress = 1024 * ( Runtime . getRuntime ( ) . availableProcessors ( ) ) ; private static final AtomicInteger totalHintsInProgress = new AtomicInteger ( ) ; private static final Map < InetAddress , AtomicInteger > hintsInProgress = new MapMaker ( ) . concurrencyLevel ( 1 ) . makeComputingMap ( new Function < InetAddress , AtomicInteger > ( ) { public AtomicInteger apply ( InetAddress inetAddress ) { } } ) ; private static final AtomicLong totalHints = new AtomicLong ( ) ; private StorageProxy ( ) { } public static void mutate ( List < ? extends IMutation > mutations , ConsistencyLevel consistency_level ) throws TimeoutException , UnavailableException { } public static IWriteResponseHandler performWrite ( IMutation mutation , ConsistencyLevel consistency_level , String localDataCenter , StorageProxy . WritePerformer performer ) throws IOException , TimeoutException , UnavailableException { } private static Collection < InetAddress > getWriteEndpoints ( String table , ByteBuffer key ) { } public static void sendToHintedEndpoints ( final RowMutation rm , Collection < InetAddress > targets , IWriteResponseHandler responseHandler , String localDataCenter , ConsistencyLevel consistency_level ) throws IOException , TimeoutException { } public static Future < Void > scheduleLocalHint ( final RowMutation mutation , final InetAddress target , final IWriteResponseHandler responseHandler , final ConsistencyLevel consistencyLevel ) throws IOException { } private static void sendMessages ( String localDataCenter , Map < String , Multimap < Message , InetAddress > > dcMessages , IWriteResponseHandler handler ) throws IOException { } private static void insertLocal ( final RowMutation rm , final IWriteResponseHandler responseHandler ) { } public static IWriteResponseHandler mutateCounter ( CounterMutation cm , String localDataCenter ) throws IOException , TimeoutException , UnavailableException { } private static InetAddress findSuitableEndpoint ( String table , ByteBuffer key , String localDataCenter ) throws UnavailableException { } public static IWriteResponseHandler applyCounterMutationOnLeader ( CounterMutation cm , String localDataCenter ) throws IOException , TimeoutException , UnavailableException { } public static IWriteResponseHandler applyCounterMutationOnCoordinator ( CounterMutation cm , String localDataCenter ) throws IOException , TimeoutException , UnavailableException { } private static Runnable counterWriteTask ( final IMutation mutation , final Collection < InetAddress > targets , final IWriteResponseHandler responseHandler , final String localDataCenter , final ConsistencyLevel consistency_level ) { } public static List < Row > read ( List < ReadCommand > commands , ConsistencyLevel consistency_level ) throws IOException , TimeoutException , InvalidRequestException , UnavailableException { } private static List < Row > fetchRows ( List < ReadCommand > initialCommands , ConsistencyLevel consistency_level ) throws IOException , TimeoutException , UnavailableException { } static class LocalReadRunnable extends StorageProxy . DroppableRunnable { private final ReadCommand command ; private final ReadCallback < Row > handler ; private final long start = System . currentTimeMillis ( ) ; LocalReadRunnable ( ReadCommand command , ReadCallback < Row > handler ) { } protected void runMayThrow ( ) throws IOException { } } static < T > ReadCallback < T > getReadCallback ( IResponseResolver < T > resolver , IReadCommand command , ConsistencyLevel consistencyLevel , List < InetAddress > endpoints ) { } public static List < Row > getRangeSlice ( RangeSliceCommand command , ConsistencyLevel consistency_level ) throws IOException , TimeoutException , UnavailableException { if ( StorageProxy . logger . isDebugEnabled ( ) ) <START_BUG> StorageProxy . logger . debug ( command . toString ( ) ) ; <END_BUG> long startTime = System . nanoTime ( ) ; List < Row > rows ; try { rows = new ArrayList < Row > ( command . max_keys ) ; List < AbstractBounds > ranges = StorageProxy . getRestrictedRanges ( command . range ) ; for ( AbstractBounds range : ranges ) { List < InetAddress > liveEndpoints = StorageService . instance . getLiveNaturalEndpoints ( command . keyspace , range . right ) ; DatabaseDescriptor . getEndpointSnitch ( ) . sortByProximity ( FBUtilities . getBroadcastAddress ( ) , liveEndpoints ) ; if ( ( ( consistency_level == ( ConsistencyLevel . ONE ) ) && ( ! ( liveEndpoints . isEmpty ( ) ) ) ) && ( liveEndpoints . get ( 0 ) . equals ( FBUtilities . getBroadcastAddress ( ) ) ) ) { if ( StorageProxy . logger . isDebugEnabled ( ) ) StorageProxy . logger . debug ( "local<seq2seq4repair_space>range<seq2seq4repair_space>slice" ) ; ColumnFamilyStore cfs = Table . open ( command . keyspace ) . getColumnFamilyStore ( command . column_family ) ; try { rows . addAll ( cfs . getRangeSlice ( command . super_column , range , command . max_keys , QueryFilter . getFilter ( command . predicate , cfs . getComparator ( ) ) ) ) ; } catch ( ExecutionException e ) { throw new RuntimeException ( e . getCause ( ) ) ; } catch ( InterruptedException e ) { throw new AssertionError ( e ) ; } } else { RangeSliceCommand c2 = new RangeSliceCommand ( command . keyspace , command . column_family , command . super_column , command . predicate , range , command . max_keys ) ; RangeSliceResponseResolver resolver = new RangeSliceResponseResolver ( command . keyspace , liveEndpoints ) ; ReadCallback < Iterable < Row > > handler = StorageProxy . getReadCallback ( resolver , command , consistency_level , liveEndpoints ) ; handler . assureSufficientLiveNodes ( ) ; for ( InetAddress endpoint : liveEndpoints ) { MessagingService . instance ( ) . sendRR ( c2 , endpoint , handler ) ; if ( StorageProxy . logger . isDebugEnabled ( ) ) StorageProxy . logger . debug ( ( ( ( "reading<seq2seq4repair_space>" + c2 ) + "<seq2seq4repair_space>from<seq2seq4repair_space>" ) + endpoint ) ) ; } try { for ( Row row : handler . get ( ) ) { rows . add ( row ) ; StorageProxy . logger . debug ( "range<seq2seq4repair_space>slices<seq2seq4repair_space>read<seq2seq4repair_space>{}" , row . key ) ; } FBUtilities . waitOnFutures ( resolver . repairResults , DatabaseDescriptor . getRpcTimeout ( ) ) ; } catch ( TimeoutException ex ) { if ( StorageProxy . logger . isDebugEnabled ( ) ) StorageProxy . logger . debug ( "Range<seq2seq4repair_space>slice<seq2seq4repair_space>timeout:<seq2seq4repair_space>{}"

Fix:
StorageProxy . logger . debug ( "Command//ConsistencyLevel<seq2seq4repair_space>is<seq2seq4repair_space>{}//{}" , command . toString ( ) , consistency_level ) ;